Method of securing the knives in paper-pulp-grinding engin es



(No Model.)

' 'JJH. HORNE." METHOD OF SECURING THE KNIVES IN'PAPER' PULP. GRINDINGENGINES.

Patented Main 4, 1884.

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METHOD OF SECURING THE KNIVES IN PAPER-PULP-GRINDING ENGINES.

SPECIFICATION forming part of Letters Patent No. 294,387, dated March 4,1884:,

Application filed December 19,1883. (No model.)

To all whom it may concern.-

Be it known that I, JOHN HENRY HORNE, a citizen of the United States,residing at Lawrence, in the county of Essex and State of Massachusetts,haveinvented certain new and useful Improvements in the Method ofSecuring the Knives in PapenPulp-Grinding Engines; and I do herebydeclare the following to be a full, clear, and exact description of theinvention, such aswill enable others skilled in the art to which itappertains to make and use the same, reference being had to theaccompanying drawings, and to letters or figures of reference markedthereon, which form a part of this specification.

The object of this invention is to provide improved means for securingthe knives to the grinding-rolls of pulpengines; and the said inventionconsists in the peculiar construction and combination of the bar and theannular ribs, by means of which said knives are attached to the roll, aswell as to the manner of inserting and looking said bars.

The class of engines to which this invention particularly applies thoughit can be adapted to any shaped rollconsists of ashell in the form of afrustum of a cone, the inner peripheryof which is furnished with knives,and a plug or cone of corresponding shape, but somewhat smaller, whoseexternal periphery is likewise provided with knives; This cone fits intothe shell above mentioned, and is capable of lateral adjustment therein.

Hitherto there have been various methods of attaching knives togrinding-rolls. Prominent among them are- First. One in which the knivesare secured to the plug or cone by a sliding bayonet-catch, andnecessitates the cutting of parallel annular grooves with undercut slotsupon the surface of the shell.

Secondly. The knives are provided with a series of lips, and the ribsupon the plug are recessed both radially and laterally to combine andunite with the. lips on the knives; hence knives of different thicknesscannot be inserted, as their thickness is limited by the width of theradial slots in which each fits.

Thirdly. The annular ribs are undercut and correspond to the bevel ofthe knife, but the knives extend only between two adjacent ribs.

This is in order to slip and lock them in place,

- rolls.

The drawings accompanying this specification represent, in Figure 1,asectional elevation of a grinding-roll embodying my invention, and inFig.- 2 an enlarged vertical crosssection through one of the annularribs at the point where the knives are inserted.

In such drawings, Arepresents the roll or plug, so called, of an enginebelonging to the-class above described. Upon this roll or cone is fitteda shell, B, of iron, brass, or other suitable material, upon which arecast ribs 0 C, &c., integral therewith but I prefer in many cases toshrink on these ribs, which are cast or 7 turned with a certain degreeof under cutor bevel. To make this prominent, the bevel is somewhatexaggerated in the drawings, as it really is but very slight. Theseannular ribs are continuous and extend entirely around the surface ofthe cone, and there may be as many as thought necessary to securelyfasten the knives to the roll. The knife, which is shown at D, is ofsteel and of the ordinary thickness of grinding-bars of thisdescription; but its lower edge is provided with slots, in number equalto the number of ribs upon the roll, and are dovetailed or beveled tosnugly fit the bevel on the ribs, that when the knife is in place itshall firmly rest on the shell B, while the ribs hold it from movingradially, and the ,usualwood filling prevents any lateral displacementarising from jars or blows incidental to work of this kind.

In order to introduce and lock the knives upon the roll, I take anypoint upon the ribs and draw a line in direct alignment with thelongitudinal axis of the roll. At these points where said line cuts theribs, I out slots of any desired width, sufficient to admit a knife ofthe very heaviest description, these slots are to be all of the samewidth, and arenot to be cut through the rib, but simply as shown in-Fig.2.

As shown in the drawings, the width of the openings a av on the knifecorresponds nearlybut slightly larger-with the width b b of the ribs,where they unite with the shell B of the roll. The width of the upperportion, 0 c, of the slots E E in the knife corresponds with thegreatest-width of the ribs 0 O, as shown at (Z d, &c.; hence it is onlynecessary to cut away the rib, so that its narrowest portion shallextend to its outer surface. To insert the knife in the roll, it is 110wheld in alignment with that point on the ribs, as shown in the drawingsat e c c, &c., as cut away. It is then lowered gradually until its loweredge rests upon the surface of the shell, and any movement laterally ineither direction locks it upon the roll. The knife is 110w pushed alonguntil it is in its proper position, resting against a piece of woodfilling, previously inserted, when a second knife is slipped in and woodfilling laid between the two, and so on until the roll is completelyfilled.

To expedite the filling, I cut, diametrically opposite the first row ofslots, a second row; hence, in filling, the first bar or knife insertedis pushed but ninety degrees or quarter around, when it reaches itsproper position.

By this mode of fastening, I do away with a large amount of labor nowexpended in securing the knives to rolls by planing slots laterally andradially through the ribs, and hence can produce a finished roll muchmore expeditiously and cheaply. Moreover, by this method I can take anyold roll, as heretofore made, turn off the slotted ribs, shrink on newones, beveled in the manner described, insert new knives, and complete aroll to all intents and purposes new. Furthermore, the slots in theknives being made of a uniform shape to correspond to the shape of theribs, any knife will fit any roll, provided they are of the same length,and, new knives being shipped, the roll can be filled at the mill.

It will be seen that a further advantage is obtained by my method, as itis evident that knives of any thickness can be inserted in the roll, astheir introduction is dependent on the width of the slot 0, and not oneach individual slot, as heretofore. I therefore take the precaution tomake the slot 0 e sufficiently wide at first to permit the insertion ofthe heaviest kind of knives.

I omitted to mention that in filling rolls of this type, in which oneend is larger than the other, it is found necessary to insert a shortbar between each long one. This short bar extends to the middle of theroll. I therefore propose, in certain cases, to cut the long bars in thecenter, as shown in Fig. 1 by the dotted line 00,- hence all the barswill be of the same length and can be put in indiscriminately, thesmaller end of the roll containing just half as many knives or bars asthe large one, when filled and ready for use. Every other bar at thelarge end rests at the center of the roll in alignment with each bar atthe small end, and forms, to all intents and purposes, an integral bar.By this means a roll can be filled more expeditiously.

I am aware that it is not new to attach grinding bars or knives to theexterior of a fitted upon ribs, (some of the ribs and recesses in theknives being dovetailed,) clamping devices being used in addition tohold said knives or bars on the cone.

I claim 1. A pulp-grinding cone having a series of dovetailed annularribs cast therewith or shrunk thereon, each rib being recessed on thesame longitudinal line, so as to leave its external width at that pointno greater than the width of its base or line of junction with saidcone, substantially as set forth.

2. A series of bars for the knives of a pulpgrinder, each bar beingprovided with a series of dovetailed or inwardly-flaring slots or reeesses, in combination with a grinding device having a series ofdovetailed annular ribs corresponding, respeetivcly, in position to saidslots, each rib being recessed on the same 1011- gitudinal line, so asto leave its width at that point uniform from the outside to the base,said width corresponding to the width of the neck of corresponding slotor recess in the bars, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

' JOHN HENRY HORNE.

Vitnesses:

H. E. LODGE, A. F. IIAYDEN.

